Fuel cells, which are sometimes referred to as electrochemical conversion cells, produce electrical energy by processing reactants, for example, through the oxidation and reduction of hydrogen and oxygen. Hydrogen can be a very attractive fuel because it is clean and it can be used to produce electricity efficiently in a fuel cell. The automotive industry has expended significant resources in the development of hydrogen fuel cells as a source of power for vehicles. Vehicles powered by hydrogen fuel cells could be more efficient and generate fewer emissions than today's vehicles employing internal combustion engines.
In some fuel cell systems, hydrogen or a hydrogen-rich gas is supplied as a reactant through a flowpath to the anode side of a fuel cell, while oxygen (such as in the form of atmospheric oxygen) is supplied as a reactant through a separate flowpath to the cathode side of the fuel cell. The anode and cathode facilitate the electrochemical conversion of the reactants into electrons and positively charged ions (for the hydrogen) and negatively charged ions and ultimately water (for the oxygen). An electrolyte layer separates the anode from the cathode to allow the selective passage of ions to pass from the anode to the cathode while simultaneously prohibiting the passage of the generated electrons, which instead are forced to flow through an external electrically-conductive circuit (such as, a load) to perform useful work before recombining with the charged ions at the cathode. The combination of the positively and negatively charged ions at the cathode results in the production of non-polluting water as a byproduct of the reaction.
A conventional proton exchange membrane (“PEM”) fuel cell may comprise a polymer electrolyte membrane (or a proton exchange membrane) with electrode layers on both sides of the polymer membrane forming a membrane electrode assembly (“MEA”). The membrane electrode assembly may be positioned between a pair of gas diffusion media layers, and a cathode plate and an anode plate are placed outside of the gas diffusion media layers. The components are compressed to form a fuel cell.
Fuel cells, however, suffer from drawbacks that can decrease the life of a fuel cell. For example, a phenomenon known as “mud cracking” can occur during formation of catalyst ink electrodes. Mud cracking is a network of cracks formed in the surface of the catalyst electrode. The network of cracks can undesirably impact the performance of the fuel cell, including for example, reducing the effective stiffness of the electrode. In addition, during operation of fuel cells, the membrane can experience cracking and failure due to a lack of mechanical integrity.
Therefore, alternative fuel cells, membrane electrode assemblies, and methods for fabricating membrane electrode assemblies are disclosed herein.